/**
 * Chartsheet structure check.
 *
 * A chartsheet (`xl/chartsheets/sheetN.xml`) must contain a `<drawing>`
 * reference — the chart itself is always in the linked drawing part.
 * Without it, Excel shows an empty chart sheet.
 */
import type { ValidationContext } from "./context.js";
export declare function checkChartsheet(ctx: ValidationContext): void;